// script.aculo.us slider.js v1.7.0, Fri Jan 19 19:16:36 CET 2007

// Copyright (c) 2005, 2006 Marty Haught, Thomas Fuchs
//
// script.aculo.us is freely distributable under the terms of an MIT-style license.
// For details, see the script.aculo.us web site: http://script.aculo.us/


if(!Control) var Control = {};
Control.Slider = Class.create();

// options:
//  axis: 'vertical', or 'horizontal' (default)
//
// callbacks:
//  onChange(value)
//  onSlide(value)
Control.Slider.prototype = {
  initialize: function(handle, track, options) {
	var slider = this;

	if(handle instanceof Array) {
	  this.handles = handle.collect( function(e) { return $(e) });
	} else {
	  this.handles = [$(handle)];
	}

	this.track   = $(track);
	this.options = options || {};

	this.axis      = this.options.axis || 'horizontal';
	this.increment = this.options.increment || 1;
	this.step      = parseInt(this.options.step || '1');
	this.range     = this.options.range || $R(0,1);

	this.value     = 0; // assure backwards compat
	this.values    = this.handles.map( function() { return 0 });
	this.spans     = this.options.spans ? this.options.spans.map(function(s){ return $(s) }) : false;
	this.options.startSpan = $(this.options.startSpan || null);
	this.options.endSpan   = $(this.options.endSpan || null);

	this.restricted = this.options.restricted || false;

	this.maximum   = this.options.maximum || this.range.end;
	this.minimum   = this.options.minimum || this.range.start;

	// Will be used to align the handle onto the track, if necessary
	this.alignX = parseInt(this.options.alignX || '0');
	this.alignY = parseInt(this.options.alignY || '0');

	this.trackLength = this.maximumOffset() - this.minimumOffset();

	this.handleLength = this.isVertical() ?
	  (this.handles[0].offsetHeight != 0 ?
		this.handles[0].offsetHeight : this.handles[0].style.height.replace(/px$/,"")) :
	  (this.handles[0].offsetWidth != 0 ? this.handles[0].offsetWidth :
		this.handles[0].style.width.replace(/px$/,""));

	this.active   = false;
	this.dragging = false;
	this.disabled = false;

	if(this.options.disabled) this.setDisabled();

	// Allowed values array
	this.allowedValues = this.options.values ? this.options.values.sortBy(Prototype.K) : false;
	if(this.allowedValues) {
	  this.minimum = this.allowedValues.min();
	  this.maximum = this.allowedValues.max();
	}

	this.eventMouseDown = this.startDrag.bindAsEventListener(this);
	this.eventMouseUp   = this.endDrag.bindAsEventListener(this);
	this.eventMouseMove = this.update.bindAsEventListener(this);

	// Initialize handles in reverse (make sure first handle is active)
	this.handles.each( function(h,i) {
	  i = slider.handles.length-1-i;
	  slider.setValue(parseFloat(
		(slider.options.sliderValue instanceof Array ?
		  slider.options.sliderValue[i] : slider.options.sliderValue) ||
		 slider.range.start), i);
	  Element.makePositioned(h); // fix IE
	  Event.observe(h, "mousedown", slider.eventMouseDown);
	});

	Event.observe(this.track, "mousedown", this.eventMouseDown);
	Event.observe(document, "mouseup", this.eventMouseUp);
	Event.observe(document, "mousemove", this.eventMouseMove);

	this.initialized = true;
  },
  dispose: function() {
	var slider = this;
	Event.stopObserving(this.track, "mousedown", this.eventMouseDown);
	Event.stopObserving(document, "mouseup", this.eventMouseUp);
	Event.stopObserving(document, "mousemove", this.eventMouseMove);
	this.handles.each( function(h) {
	  Event.stopObserving(h, "mousedown", slider.eventMouseDown);
	});
  },
  setDisabled: function(){
	this.disabled = true;
  },
  setEnabled: function(){
	this.disabled = false;
  },
  getNearestValue: function(value){
	if(this.allowedValues){
	  if(value >= this.allowedValues.max()) return(this.allowedValues.max());
	  if(value <= this.allowedValues.min()) return(this.allowedValues.min());

	  var offset = Math.abs(this.allowedValues[0] - value);
	  var newValue = this.allowedValues[0];
	  this.allowedValues.each( function(v) {
		var currentOffset = Math.abs(v - value);
		if(currentOffset <= offset){
		  newValue = v;
		  offset = currentOffset;
		}
	  });
	  return newValue;
	}
	if(value > this.range.end) return this.range.end;
	if(value < this.range.start) return this.range.start;
	return value;
  },
  setValue: function(sliderValue, handleIdx){
	if(!this.active) {
	  this.activeHandleIdx = handleIdx || 0;
	  this.activeHandle    = this.handles[this.activeHandleIdx];
	  this.updateStyles();
	}
	handleIdx = handleIdx || this.activeHandleIdx || 0;
	if(this.initialized && this.restricted) {
	  if((handleIdx>0) && (sliderValue<this.values[handleIdx-1]))
		sliderValue = this.values[handleIdx-1];
	  if((handleIdx < (this.handles.length-1)) && (sliderValue>this.values[handleIdx+1]))
		sliderValue = this.values[handleIdx+1];
	}
	sliderValue = this.getNearestValue(sliderValue);
	this.values[handleIdx] = sliderValue;
	this.value = this.values[0]; // assure backwards compat

	this.handles[handleIdx].style[this.isVertical() ? 'top' : 'left'] =
	  this.translateToPx(sliderValue);

	this.drawSpans();
	if(!this.dragging || !this.event) this.updateFinished();
  },
  setValueBy: function(delta, handleIdx) {
	this.setValue(this.values[handleIdx || this.activeHandleIdx || 0] + delta,
	  handleIdx || this.activeHandleIdx || 0);
  },
  translateToPx: function(value) {
	return Math.round(
	  ((this.trackLength-this.handleLength)/(this.range.end-this.range.start)) *
	  (value - this.range.start)) + "px";
  },
  translateToValue: function(offset) {
	return ((offset/(this.trackLength-this.handleLength) *
	  (this.range.end-this.range.start)) + this.range.start);
  },
  getRange: function(range) {
	var v = this.values.sortBy(Prototype.K);
	range = range || 0;
	return $R(v[range],v[range+1]);
  },
  minimumOffset: function(){
	return(this.isVertical() ? this.alignY : this.alignX);
  },
  maximumOffset: function(){
	return(this.isVertical() ?
	  (this.track.offsetHeight != 0 ? this.track.offsetHeight :
		this.track.style.height.replace(/px$/,"")) - this.alignY :
	  (this.track.offsetWidth != 0 ? this.track.offsetWidth :
		this.track.style.width.replace(/px$/,"")) - this.alignY);
  },
  isVertical:  function(){
	return (this.axis == 'vertical');
  },
  drawSpans: function() {
	var slider = this;
	if(this.spans)
	  $R(0, this.spans.length-1).each(function(r) { slider.setSpan(slider.spans[r], slider.getRange(r)) });
	if(this.options.startSpan)
	  this.setSpan(this.options.startSpan,
		$R(0, this.values.length>1 ? this.getRange(0).min() : this.value ));
	if(this.options.endSpan)
	  this.setSpan(this.options.endSpan,
		$R(this.values.length>1 ? this.getRange(this.spans.length-1).max() : this.value, this.maximum));
  },
  setSpan: function(span, range) {
	if(this.isVertical()) {
	  span.style.top = this.translateToPx(range.start);
	  span.style.height = this.translateToPx(range.end - range.start + this.range.start);
	} else {
	  span.style.left = this.translateToPx(range.start);
	  span.style.width = this.translateToPx(range.end - range.start + this.range.start);
	}
  },
  updateStyles: function() {
	this.handles.each( function(h){ Element.removeClassName(h, 'selected') });
	Element.addClassName(this.activeHandle, 'selected');
  },
  startDrag: function(event) {
	if(Event.isLeftClick(event)) {
	  if(!this.disabled){
		this.active = true;

		var handle = Event.element(event);
		var pointer  = [Event.pointerX(event), Event.pointerY(event)];
		var track = handle;
		if(track==this.track) {
		  var offsets  = Position.cumulativeOffset(this.track);
		  this.event = event;
		  this.setValue(this.translateToValue(
		   (this.isVertical() ? pointer[1]-offsets[1] : pointer[0]-offsets[0])-(this.handleLength/2)
		  ));
		  var offsets  = Position.cumulativeOffset(this.activeHandle);
		  this.offsetX = (pointer[0] - offsets[0]);
		  this.offsetY = (pointer[1] - offsets[1]);
		} else {
		  // find the handle (prevents issues with Safari)
		  while((this.handles.indexOf(handle) == -1) && handle.parentNode)
			handle = handle.parentNode;

		  if(this.handles.indexOf(handle)!=-1) {
			this.activeHandle    = handle;
			this.activeHandleIdx = this.handles.indexOf(this.activeHandle);
			this.updateStyles();

			var offsets  = Position.cumulativeOffset(this.activeHandle);
			this.offsetX = (pointer[0] - offsets[0]);
			this.offsetY = (pointer[1] - offsets[1]);
		  }
		}
	  }
	  Event.stop(event);
	}
  },
  update: function(event) {
   if(this.active) {
	  if(!this.dragging) this.dragging = true;
	  this.draw(event);
	  // fix AppleWebKit rendering
	  if(navigator.appVersion.indexOf('AppleWebKit')>0) window.scrollBy(0,0);
	  Event.stop(event);
   }
  },
  draw: function(event) {
	var pointer = [Event.pointerX(event), Event.pointerY(event)];
	var offsets = Position.cumulativeOffset(this.track);
	pointer[0] -= this.offsetX + offsets[0];
	pointer[1] -= this.offsetY + offsets[1];
	this.event = event;
	this.setValue(this.translateToValue( this.isVertical() ? pointer[1] : pointer[0] ));
	if(this.initialized && this.options.onSlide)
	  this.options.onSlide(this.values.length>1 ? this.values : this.value, this);
  },
  endDrag: function(event) {
	if(this.active && this.dragging) {
	  this.finishDrag(event, true);
	  Event.stop(event);
	}
	this.active = false;
	this.dragging = false;
  },
  finishDrag: function(event, success) {
	this.active = false;
	this.dragging = false;
	this.updateFinished();
  },
  updateFinished: function() {
	if(this.initialized && this.options.onChange)
	  this.options.onChange(this.values.length>1 ? this.values : this.value, this);
	this.event = null;
  }
}